Lloyd's broker Horace Holman and Co will close its business and cease trading.
The broker, which separated from Holmans in the early 1980s, will stop placing new business "in the near future".
A Lloyd's source said: "They will continue to place business until such time as alternative arrangements have been made for the servicing of their clients, whereupon they expect to run-off their business in an orderly and solvent manner."
A Lloyd's source suggested the broker no longer views its market, marine and contingency, as a profitable one.
He said: "The consistently low rates in the marine market mean brokers are finding it hard to find the market a profitable one. Clients will now have to go elsewhere."
Horace Holman managing director Arwyn Powell said: "It was always our intention to close the business around this time. The level of brokerage has fallen away as we anticipated."
It is understood that the broker will look to off-load clients onto other, existing producers.